The invention is directed to improvements in floodgate structures, for selectively closing off flood access areas during periods of high water inundation. For this service, the gate panel structure remains in a retracted or inoperative position for long periods of time, perhaps more than a year. When high water inundation is anticipated, the floodgate is moved into a position to serve as a barrier against such inundation.
Pursuant to the present invention, an improved floodgate structure is provided in which a particularly advantageous form of sealing means is provided, for sealing the peripheral areas of the gate structure against the flow of water under pressure, when the panel is in its active position and hydrostatic pressure is present.
Pursuant to one aspect of the invention, peripheral portions of the floodgate panel are provided on opposite sides with redundant seals, including a continuous, pneumatically inflatable sealing means on the upstream or pressure side of the floodgate, and a hydrostatically loaded, continuous sealing skirt on the opposite or downstream side of the gate panel. The arrangement of the seals is such that, when the upstream seal is deflated, the gate panel is easily raised and lowered in its guiding and supporting structure. When the gate is in its operative position, the upstream sealing means is inflated, bodily urging the gate panel in a downstream direction to bring the mechanical sealing element into sealing contact with the support structure and mechanically loading that seal sufficiently to make it effective. In the arrangement of the invention, if the panel becomes hydrostatically loaded by a high water condition, the mechanically loaded skirt seal is held in sealing contact with its adjacent structure by the hydrostatic force, as well as by the force of the upstream, inflatable sealing elements. Accordingly, should the upstream elements become deflated for any reason, the seal will be maintained by the hydrostatically loaded skirt seal on the downstream side.
The structure of the invention is both simple and durable, so as to be capable of economically acceptable installation costs, while at the same time being reliably operational under rather severe duty conditions.
For a more complete understanding of the above and other features and advantages of the invention, reference should be made to the following description of a preferred embodiment of the invention, and to the accompanying drawing.